Dredge swell compensator apparatus

Abstract

An apparatus for maintaining a uniform grade of the surface being excavated or leveled by a waterborne dredge. The apparatus includes a shore mounted laser that projects a horizontal beam which is utilized to establish a reference plane, a dredge mounted photo receiver responsive to the beam from said shore mounted laser, a hydraulic system for repositioning the dredge cutter in response to changes of position of the dredge relative to the reference plane established by the laser beam. The hydraulic system includes a specifically designed pulley arrangement which raises and lowers the dredge ladder to maintain the cutter at a constant elevation.

What is claimed is: 
     
       1. A waterborne dredge compensating system for maintaining a uniform grade comprising: a. a shore mounted laster for projecting a horizontal beam of radiant energy, said horizontal beam establishing a reference plane of known elevation;   b. a photo receiver having a plurality of vertically arranged photo sensitive arrays, said photo receiver being mounted on a waterborne dredge and being so oriented that said horizontal beam of radiant energy impinges on said photo receiver;   c. a dredge ladder having one end mounted on said waterborne dredge such that said ladder is vertically moveable and having a dredge cutter mounted on its other end;   d. a hydraulic system, activated by output signals from said photo receiver, mounted on said waterborne dredge;   e. a winch mounted on said dredge;   f. an A-frame, mounted on said waterborne dredge, supporting a block and tackle assembly, said block and tackle assembly including a first pulley block having a flat horizontal upper plate; and   g. a vertical support rod, said vertical support rod having its bottom end secured to said flat horizontal upper plate of said first pulley block and wherein said photo receiver is secured to the top end of said vertical support rod, whereby said photo receiver moves up and down when said first pulley block moves up and down, respectively.   
     
     
       2. The apparatus of claim 1 wherein said block and tackle further includes: a. a pin mounted on said A-frame;   b. a large upper pulley mounted on said pin, said first pulley block being suspended below said large upper pulley; and   c. a second pulley block suspended below said first pulley block.   
     
     
       3. The apparatus of claim 2 wherein said hydraulic system includes: a. a first hydraulic cylinder having a first end mounted on said pin secured to said A-frame adjacent one side of said large upper pulley and a second end secured to said flat horizontal upper plate of said first pulley block; and   b. a second hydraulic cylinder having a first end mounted on said pin secured to said A-frame adjacent the other side of said large upper pulley and a second end secured to said flat horizontal upper plate of said first pulley block.   
     
     
       4. A waterborne dredge compensating system for maintaining a uniform grade comprising: a. a shore mounted laser for projecting a horizontal beam of radiant energy, said horizontal beam establishing a reference plane of known elevation;   b. a photo receiver having three photo sensitive arrays mounted one on top of the other, said photo receiver being mounted on a waterborne dredge and being so oriented that said horizontal beam of radiant energy impinges on said photo receiver, said photo receiver produces an output signal when said laser beam impinges on the uppermost one of said three photo sensitive arrays, produces an output when said laser beam impinges on the lowermost one of said three photo sensitive arrays and produces no output signal when said laser beam impinges on the center one of said three photo sensitive arrays;   c. a dredge ladder having one end mounted on said waterborne dredge such that said ladder is vertically moveable and having a dredge cutter mounted on its other end;   d. a hydraulic system, activated by output signals from said photo receiver, mounted on said waterborne dredge;   e. a winch mounted on said dredge; and   f. an A-frame, mounted on said waterborne dredge, supporting a block and tackle assembly, said block and tackle assembly including a first pulley block having a flat horizontal upper plate.   
     
     
       5. The apparatus of claim 4, wherein said block and tackle further includes; a. a pin mounted on said A-frame;   b. a large upper pulley mounted on said pin, said first pulley block being suspended below said large upper pulley; and   c. a second pulley block suspended below said first pulley block.   
     
     
       6. The apparatus of claim 5 wherein said hydraulic system includes: a. a first hydraulic cylinder having a first end mounted on said pin secured to said A-frame adjacent one side of said large upper pulley and a second end secured to said flat horizontal upper plate of said first pulley block; and   b. a second hydraulic cylinder having a first end mounted on said pin secured to said A-frame adjacent the other side of said large upper pulley and a second end secured to said flat horizontal upper plate of said first pulley block.